81636377835 has 32 divisors (see below), whose sum is σ = 137604591360. Its totient is φ = 41214331008.

The previous prime is 81636377831. The next prime is 81636377887. The reversal of 81636377835 is 53877363618.

It is not a de Polignac number, because 81636377835 - 2² = 81636377831 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (81636377831) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 236764 + ... + 468326.

It is an arithmetic number, because the mean of its divisors is an integer number (4300143480).

Almost surely, 2^81636377835 is an apocalyptic number.

81636377835 is a deficient number, since it is larger than the sum of its proper divisors (55968213525).

81636377835 is a wasteful number, since it uses less digits than its factorization.

81636377835 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232827.

The product of its digits is 15240960, while the sum is 57.

The spelling of 81636377835 in words is "eighty-one billion, six hundred thirty-six million, three hundred seventy-seven thousand, eight hundred thirty-five".